The invention relates to a wing flap sensor unit having a position sensor for detection of a rotational position of a shaft for operation of wing flaps and having a housing which surrounds the position sensor, having an attachment means for attachment in an aircraft wing and having a connecting point for an electrical connector of the position sensor.
Relatively large aircraft, such as passenger aircraft or transport aircraft, have wing flaps and moving slats, which can be moved hydraulically in order to vary the wing profile, on their mainplanes. During a landing approach, the wing profile is set to be curved such that the lift is increased and the aircraft has sufficient lift despite the slow landing speed. There is a selection lever in the aircraft cockpit in order to control the movement of the wing flaps, via which lever the pilot sets the position of the wing flaps and slats. The input command is processed as a set position by a computer, which compares the set position with the actual position of the wing flaps and passes a control signal to a drive if there is any discrepancy between them. The drive moves ball screw spindles, which extend through the aircraft wing and completely extend or retract the wing flaps and slats, via corresponding intermediate mechanisms, by rotating several hundred times.
For reliable control of the wing flaps and slats, their current position is monitored by one or more wing flap sensors, which measure the rotational position of the ball screw spindles or of a shaft which is rigidly connected thereto. In order to achieve a reliable measurement with unambiguous settings, the revolution movement is in this case transmitted, stepped down by means of a transmission, to a position transmitter, which is moved through less than one complete revolution between an entirely retracted state and a completely extended state of one or more wing flaps or slats, as a result of which its position can clearly be associated with one flap position.
Particularly in the case of a very large aircraft, it may be necessary for the wing flaps and moving slats to be extended for a landing approach, in order to allow the aircraft to be braked reliably. If there is a defect in the movement mechanism such that wing flaps or slats cannot be moved or cannot be moved sufficiently to the predetermined position, landing may be problematic. It is therefore necessary for the wing flap sensor to reliably detect the actual position over a long time period in order to always allow control and to identify a mechanical defect early.
The wing flap sensor is arranged in the interior of an aircraft wing, is protected against external mechanical influences and comprises a housing which protects it against weather influences, water and salt, and which has interfaces, for example plugs, for electrical and signal connections.
One object of the invention is to specify a wing flap sensor which operates reliably over a long time period.